12 LEAD ECG EVOLUTION FROM PRE-HOSPITAL TO HOSPITAL ARRIVAL IN PATIENTS WITH SYMPTOMS SUSPICIOUS FOR ACUTE CV DISEASE: PROACT 3 ECG SUBSTUDY

Abstract

Prehospital triage and diagnosis of patients with STEMI enhances treatment efficiency and improves patient outcomes. However it is unclear whether prehospital ECG and cardiac biomarkers hasten the triage process or enhance treatment outcomes in patients with acute chest discomfort or dyspnea (with STEMI excluded). Accordingly, we assessed dynamic ECG metrics, peak biomarkers and 30 day death and reassessment/readmission in pre-hospital patients with acute cardiovascular disease symptoms. The Providing Rapid Out of Hospital Acute Cardiovascular Treatment-3 (PROACT-3) trial enrolled pre-hospital patients with acute chest discomfort or dyspnea. We analysed 269 with paired prehospital (EMS) and first in-hospital (IH) ECGs in a core laboratory. Subjects were categorized according to adjudicated diagnosis into 4 groups: 9(3.3%) Angina, 42(15.6%) ACS, 12(4.5%) acute heart failure (AHF), and 206(76.6%) patients with other diagnoses. Dynamic ECG changes from EMS-ECGs to IH-ECGs were compared. We categorised total ST deviation resolution (DR) according to percentage change into 3 groups: and ST DR≥ 70%, ST DR≥30%-≤70% and ST DR <30% which also includes patients who experience an increase in ST deviation. Results are reported as medians with interquartile ranges. On the EMS ECG, ST deviation was: 1.0 (0.0-2.0) Angina, 3.5 (1.5-6.5) ACS, 1.5 (1.0-2.5) AHF, and other 2.0 (0.5-4.0). The median time in minutes from EMS-ECG to IH-ECG was 76.0 (44.0, 156.0) angina, 64.5 (48.0, 112.5) ACS, 78.0 (57.0, 103.0) AHF, and 76.5 (56.0-108.0) other. ECG metrics comparing EMS to IH ECG were as follows: 28(10.4%) had no ST deviation, 32(11.9%) had persistent ST deviation, 43(16%) developed ST DR≥70%, 54(20.1%) developed ST DR≥30%-≤70%, 112(41.6%) developed ST DR≤30% - including 81 patients with ST worsening. Among patients with improved ST change i.e. ST DR>70% diagnoses were: 0% angina, 18.6% ACS, 2.3% AHF and 79.1% in other. In those patients with ST DR≤30%, the peak cardiac biomarkers were elevated (BNP ≥400 and troponin I ≥0.3) in 12/68(17.6%) BNP (≥400) and 56/86(65.1%) troponin I (≥0.3). In the total cohort 30 day death occurred in 5/269: 1 with no ST deviation, 2 with persistent ST deviation, and 2 with ST DR≥30%-≤70%. 30 day rehospitalisation/emergency reassessment occurred in: 5/43(11.6%) ST DR≥70%, 16/54(29.6%) ST DR ≥30%-≤70% and 22/112(19.6%) ST DR≤30%. In prehospital patients with suspect acute cardiovascular disease, the EMS ECG frequently demonstrates ST deviation (89.6%). Furthermore, dynamic ECG changes are frequently observed as described above. Further analysis is required to determine the correlation of these dynamic ECG findings with clinical outcomes.